Compositions for reducing hair loss and/or increasing hair regrowth

ABSTRACT

The invention relates to a composition for use in reducing hair loss and/or increasing regrowth of hair in a human subject comprising minoxidil, either a 5α-reductase inhibitor or an androgen receptor antagonist, and a prostaglandin analog. In one embodiment, the composition comprises minoxidil, a 5α-reductase inhibitor, and a prostaglandin analog, wherein the 5α-reductase inhibitor is finasteride. In another embodiment, the prostaglandin analog is latanoprost. In yet another embodiment, the composition is for topical application to a scalp. The invention also relates to the use of such a composition to reduce hair loss and/or increase regrowth of hair in a human subject.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent application Ser. No. 14/917,501, which is a continuation of PCT/CA2015/000327 filed May 22, 2015 which in turn claims priority to U.S. provisional patent application 62/002,397, filed May 23, 2014, this application also claims priority to Canadian Patent Application Ser. No. 2903734, filed Sep. 2, 2015. The disclosure of the above applications are hereby incorporated herein by reference.

FIELD OF INVENTION

The inventor has developed a composition comprising minoxidil, finasteride and a prostaglandin analogue that shows improved properties in terms of reducing hair loss and increasing hair regrowth when compared to conventional therapies, such as the topical application of a solution of 5% minoxidil.

BACKGROUND

Androgenetic alopecia(AGA) is hair loss (at scalp level) caused by the thinning of hair follicles. It is very common in men between the age of 19 and 70 years. Notably, more than 50% of Caucasian men in their fifties are affected by it. Women's hair loss mostly becomes an issue after menopause.

Alopecia occurs as a result of the transformation of terminal hair follicles, which are large, thick and pigmented, to vellus hair follicles, which are short, thin and non-pigmented. This process is known as miniaturization. Dihydrotestoterone (DHT) is believed to play a role in such a process. Testosterone is converted to DHT in the cells by the enzyme, 5α-reductase. This enzyme is found in various tissues including the hair follicle. Decreasing the levels of DHT in the hair follicle can prevent or slow down the miniaturization process. This can be accomplished either by inhibiting the conversion of testosterone to DHT or by competing with testosterone or DHT for the androgen receptors through the use of an androgen receptor antagonist.

Individuals affected by androgenetic alopecia (AGA) show a diminution of their self-esteem that can effect negatively many facets of their lives. The inventor has developed a composition for topical administration comprising minoxidil, finasteride and a prostaglandin analogue is effective in reducing hair loss and increasing hair regrowth.

There are several hair loss prevention products on the market. By way of example, minoxidil has been in use since the 1990s in topical form at 2% concentration (without prescription) and at 3% and 5% concentration (with prescription). While studies demonstrate the efficiency of 5% minoxidil over the 2% concentration, minoxidil is less than 40% effective in promoting regrowth of the hair. Minoxidil is considered the topical gold standard available for treatment of hair loss.

Another hair loss prevention product is finasteride. It is administered orally usually at a dosage of 1 mg/day. There are a number of side effects associated with the administration of finasteride including lowered libido, impotence, ejaculation disorders, allergic reactions, testicular pain, male infertility, male breast cancer and depression. At higher concentrations (5 mg), finasteride can cause benign prostate hyperplasia.

Latanoprost, a PGF_(2α) prostaglandin analog, is widely used in ophthalmology to treat open angle glaucoma and ocular hypertension. One of its side effects has been an augmentation of periocular hirsuteness, which includes a surge in the thickness, length and pigmentation of eyelashes which is to be distinguished from hair growth. Some of its other adverse effects are erythema, folliculitis, sensation of burning and erysipelas. A latanoprost ophthalmic solution has a concentration of 0.005%. It should be noted that scalp hair follicles and eyelash follicles are not identical and one cannot simply extrapolate from a drug effect on one type of hair to another.

SUMMARY

The inventor has developed a composition comprising minoxidil, either a 5α-reductase inhibitor or an androgen receptor antagonist, and a prostaglandin analogue for topical application to the scalp reduces hair loss and increases hair regrowth. Such a composition shows superior improvements to those seen for each of the components of the composition taken individually and the results obtained to date suggest that the improvements may be superior to those of the sum of the said components.

The invention relates to a composition comprising 2% to 5% minoxidil, 0.01% to 15% of a 5α-reductase inhibitor or an androgen receptor antagonist, and 0.01% to 15% of a prostaglandin analogue.

In a preferred embodiment, the invention relates to a composition comprising 2% to 5% minoxidil, 0.01% to 15% finasteride and 0.01% to 15% of a prostaglandin analogue. In one embodiment, the prostaglandin analogue is latanoprost. In another embodiment, the composition comprises 5% minoxidil, 0.1% finasteride and 0.03% latanoprost. The invention also relates to the use of a composition comprising 2% to 5% minoxidil, 0.01% to 15% finasteride and 0.01% to 15% of a prostaglandin analogue to reduce hair loss and/or increase regrowth of hair in a human subject.

BRIEF DESCRIPTION OF THE FIGURES

FIGS. 1A to 1L are a series of photographs showing the scalp of participant 1 prior to treatment and at intervals throughout the course of a six month treatment with a composition of the invention. FIGS. 1A and 1B show the scalp before treatment on the first day of month 1, FIGS. 1C and 1D show the scalp on month 2, FIGS. 1E and 1F on month 3, FIGS. 1G and 1H on month 4, FIGS. 1I and 1J on month 5 and FIGS. 1K and 1L on month 6;

FIGS. 2A to 2L are a series of photographs showing the scalp of participant 2 prior to treatment and at intervals throughout the course of a six month treatment with a composition of the invention. FIGS. 2A and 2B show the scalp before treatment on the first day of month 1, FIGS. 2C and 2D show the scalp on month 2, FIGS. 2E and 2F on month 3, FIGS. 2G and 2H on month 4, FIGS. 21 and 2J on month 5 and FIGS. 2K and 2L on month 6;

FIGS. 3A to 3L are a series of photographs showing the scalp of participant 3 prior to treatment and at intervals throughout the course of a six month treatment with a composition of the invention. FIGS. 3A and 3B show the scalp before treatment on the first day of month 1, FIGS. 3C and 3D show the scalp on month 2, FIGS. 3E and 3F on month 3, FIGS. 3G and 3H on month 4. FIGS. 3I and 3J on month 5 and FIGS. 3K and 3L on month 6;

FIGS. 4A to 4L are a series of photographs showing the scalp of participant 4 prior to treatment and at intervals throughout the course of a six month treatment with a solution of 5% minoxidil only. FIGS. 4A and 4B show the scalp before treatment on the first day of month 1, FIGS. 4C and 4D show the scalp on month 2, FIGS. 4E and 4F on month 3, FIGS. 4G and 4H on month 4. FIGS. 4I and 4J on month 5 and FIGS. 4K and 4L for month 6;

FIGS. 5A to 5L are a series of photographs showing the scalp of participant 5 prior to treatment and at intervals throughout the course of a six month treatment with a solution of 0.1% finasteride only. FIGS. 5A and 5B show the scalp before treatment on the first day of month 1, FIGS. 5C and 5D show the scalp on month 2. FIGS. 5E and 5F on month 3, FIGS. 5G and 511 on month 4, FIGS. 51 and 5J on month 5 and FIGS. 5K and 5L on month 6;

FIGS. 6A to 6L are a series of photographs showing the scalp of participant 6 prior to treatment and at intervals throughout the course of a six month treatment with a solution of 0.1% finasteride only. FIGS. 6A and 6B show the scalp before treatment on the first day of month 1, FIGS. 6C and 6D show the scalp on month 2, FIGS. 6E and 6F 6C on month 3, FIGS. 6G and 6H on month 4, FIGS. 61 and 6J on month 5 and FIGS. 6K and 6L on month 6;

FIGS. 7A to 7G are a series of photographs showing the scalp of participant 7 prior to treatment and at intervals throughout the course of a six month treatment with a solution of 0.1% finasteride only. FIGS. 7A and 7B show the scalp before treatment on the first day of month 1, FIG. 7C shows the scalp on month 2, FIG. 7D on month 3, FIG. 7E on month 4, FIG. 7F on month 5 and FIG. 7G on month 6:

FIGS. 8A to 8L are a series of photographs showing the scalp of participant 8 prior to treatment and at intervals throughout the course of a six month treatment with a solution of 0.1% finasteride only. FIGS. 8A and 8B show the scalp before treatment on the first day of month 1, FIGS. 8C and 8D show the scalp on month 2, FIGS. 8E and 8F on month 3, FIGS. 8G and 8H on month 4, FIGS. 81 and 8J on month 5 and FIGS. 8K and 8L on month 6;

FIGS. 9A to 9L are a series of photographs showing the scalp of participant 9 prior to treatment and at intervals throughout the course of a six month treatment with a solution of 0.03% latanoprost only. FIGS. 9A and 9B show the scalp before treatment on the first day of month 1, FIGS. 9C and 9D show the scalp on month 2. FIGS. 9E and 9F on month 3, FIGS. 9G and 9H on month 4, FIGS. 91 and 9J on month 5 and FIGS. 9K and 9L on month 6;

FIGS. 10A to 10L are a series of photographs showing the scalp of participant 10 prior to treatment and at intervals throughout the course of a six month treatment with a solution of 0.03% latanoprost only. FIGS. 10A and 10B show the scalp before treatment on the first day of month 1, FIGS. 10C and 10D show the scalp on month 2, FIGS. 10E and 10F on month 3, FIGS. 10G and 10H on month 4, FIGS. 10I and 10J on month 5 and FIGS. 10K and 10L on month 6.

DETAILED DESCRIPTION OF THE INVENTION

The invention relates to a composition comprising minoxidil, a 5α-reductase inhibitor or an androgen receptor antagonist and a prostaglandin analog which shows improved properties for the reduction of hair loss and for the increase of hair regrowth in human subjects, when compared to each component taken alone.

Minoxidil or (6-(1-pipedidinyl)-2,4-pyrimidinediamine 3-oxide) has the following structural formula:

Minoxidil is a crystalline solid which has a solubility in mg/ml of 75 in propylene glycol, of 44 in methanol, of 29 in ethanol, of 6.7 in 2-propanol, of 6.5 in DMSO, of 2.2 in water, of 0.5 in chloroform, and of <0.5 in acetone. Minoxidil has a pKa of 4.61.

Inhibitors of 5α-reductase inhibit the conversion of testosterone to DHT. The 5α-reductase enzyme has three different isoforms, type I, type II or type III. The inhibitors can inhibit one or more of the these isoforms. The type II form is found predominantly in the hair follicles. Finasteride is an example of a 5α-reductase type II and III inhibitor. While the composition tested comprises finasteride, it is hypothesized that other 5α-reductase inhibitors can also be used. By way of example, other suitable 5α-reductase inhibitors include dutasteride ((5α, 17β)-N-{2,5-Bis(trisfluoromethyl)phenyl}-3-oxo-4-azaandrost-1-ene-17-carboxamide), izonsteride ((4aR,10bR)-8-[(4-ethyl-1,3-benzothiazol-2-yl)sulfanyl]-4,10b-dimethyl-1,4,4a,5,6,10b-hexahydrobenzo[f] quinolin-3(2H)-one), epristeride (17-(tert-butylcarbamoyl)androsta-3,5-diene-3-carboxylic acid), lapisteride (N-[1-(4-methoxyphenyl)-1-methylethyl]-3-oxo-4-aza-5α-androst-1-ene-178-carboxamide), turosteride ((4aR,4bS,6aS,7S,9aS,9bS,11aR)-1,4a,6a-trimethyl-2-oxo-N-(propan-2-yl)-N-(propan-2-ylcarbamoyl)hexadecahydro-1H-indeno[5,4-t]quinoline-7-carboxamide) and alfatradiol (Estra-1,3,5(10)-triene-3,17α-diol). Duasteride is an inhibitor of all three forms of 5α-reductase. Lapisteride and izonsteride are types I and II inhibitors. Epristeride and turosteride are type II inhibitors.

Finasteride or ((5α,17β)-N-(1,1-Dimethylethyl)-3-oxo-4-azaandrost-1-ene-17-carboxamide) is an example of a 5α-reductase inhibitor and has the following structural formula:

Finasteride is conventionally administered orally at a daily dose of 1 mg.

Finasteride is an anhydrous crystalline solid. Finasteride is freely soluble in chloroform, DMSO, ethanol, methanol, n-propanol; sparingly soluble in propylene glycol, polyethylene glycol 400; and very slightly soluble in 0.1N HCl and 0.1N NaOH. Finasteride is not soluble in water.

Antagonists of the androgen receptors work by competing with testosterone and DHT for androgen receptor binding leading to reduced levels of DHT. Various antagonists of the androgen receptors are known. By way of example, these include flutamide (2-methyl-N-[4-nitro-3-(trifluoromethyl)phenyl]-propanamide) and topilutamide (2-Hydroxy-2-methyl-N-[4-nitro-3-(trifluoromethyl)phenyl]-3-[2,2,2-trifluoroacetyl)amino]propanamide), which is also known as fluridil. It is surmised that while the androgen receptor antagonists have a different mechanism of action than the 5α-reductase inhibitors, they share a common effect of leading to decreased levels of DHT in the hair follicle and thus could be used in the hair composition of the invention.

Latanoprost or ((5Z)-7-[(1R,2R,3R,5SO-3,5-Dihydroxy-2-[(3R)-3-hydroxy-5-phenylpentyl] cyclopentyl]-5-heptenoic acid 1-methylethyl ester) has the following structural formula:

Latanoprost is an oil. Latanoprost is very soluble in acetonitrile; freely soluble in acetone, ethanol, ethyl acetate, isopropanol, methanol and octanol. It is practically insoluble in water.

Prostaglandins regulate a number of physiological functions. It has been found that most hair cell types are endowed with prostaglandin metabolism machinery and are thus able to produce PGE₂ and/or PGF_(2α). The epithelial part of the hair bulb is the main source of prostaglandin synthesis and interconversion. From Colombe et al. (Prostaglandin Metabolism in Human Hair Follicle, Exp Dermatol. 2007 September, 16(9): 762 to 769) and as minoxidil has also been found to enhance prostaglandin endoperoxide synthase-1 (PGHS-1) activity, this suggests that prostaglandins are involved in hair growth and differentiation control and that there is a link between prostaglandin synthesis and hair growth. Minoxidil has been demonstrated to be a potent activator of purified PGHS-1 by assaying oxygen consumption in prostaglandin PGE₂ production suggesting that the mechanism beyond the hair-growth stimulating effect of minoxidil is stimulation of PGE₂ synthesis (Michelet et al., Activation of Cytoprotected Prostaglandin Synthase-1 by Minoxidil as a Possible Explanation for Its Hair Growth-Stimulating Effect, J. Invest Dermatol 1997: 108: 205-209). This has been confirmed by the role of PGHS-2 in the control of hair cycle (Muller-Decker et al., Expression of Cyclo-Oxygenase Isozymes During Morphogenesis and Cycling of Telage Hair Follicles in Mouse Skin, J. Invest Dermatol 2003: 121: 661-668). It has been shown that the human hair follicle can sustain a complete PGE₂ and PGF_(2α) metabolism. Human hair follicle express (i) mPGES-1, mPGES-2 and cPGES which catalyse PGE₂ synthesis from PGH₂, (ii) AKR1C3/PGFS which converts PGH₂ into PGF_(2α) and (iii) CDR1 and AKR1C1 aldo-ketoreductase, which could control PGE₂/PGF_(2α) interconversion. As such, it has been shown that human hair follicles appear fully enzymatically equipped to self-process prostaglandin synthesis and metabolism, meaning PGE₂ and PGF_(2α) could be produced and inter-converted by hair follicles. While the composition tested comprised latanoprost, a PGF_(2α) prostaglandin analogue, it is surmised that other prostaglandin analogues can also be used given the role played by prostaglandin in hair growth and differentiation. By way of example, other suitable prostaglandin analogues include travoprost, bimatoprost, tafluprost and unoprostone.

The composition of the invention comprises 2% to 5% minoxidil, 0.01% to 15% of a 5α-reductase inhibitor of of an androgen receptor antagonist and 0.01% to 15% of a prostaglandin analogue. In a preferred embodiment, the composition comprises 2% to 5% minoxidil, 0.01% to 5% finasteride and 0.01% to 5% of a prostaglandin analogue. In a more preferred embodiment, the composition comprises 5% minoxidil, 0.5% finasteride and 0.1% of a prostaglandin analogue. In a yet other preferred embodiment, the prostaglandin analogue is latanoprost, travoprost, bimatoprost, tafluprost or unoprostone. In a further preferred embodiment, the prostaglandin analogue is latanoprost. In an even more preferred embodiment, the composition comprises 5% minoxidil, 0.1% finasteride and 0.03% latanoprost as set out in Table 1 below.

In order to demonstrate the improved properties of a composition suitable for topical application comprising minoxidil, finasteride and a prostaglandin analogue, latanoprost, the composition was compared to compositions comprising 5% minoxidil only, 0.1% finasteride only and 0.03% latanoprost only. The various compositions were prepared as follows.

Example 1 Preparation of Composition Comprising Finasteride, Latanoprost and Minoxidil

In order to prepare the composition, latanoprost was diluted to obtain a concentration of 10,000 mcg/ml of solute on in absolute ethyl alcohol, and prepared as a stock solution and kept in a freezer to enhance stability (−20° C.). Absolute ethyl alcohol was mixed with propylene glycol and heated to 55°-65° C. Minoxidil powder was then added to the alcohol/propylene glycol mixture. In a containment hood, finasteride was added to the solution and stirred until dissolved. The preparation was cooled to room temperature. Ethoxy diglycol and latanoprost were added to the cooled solution and stirred well, until in solution. The final solution was brought to volume with absolute ethyl alcohol.

The amounts used are set out in Table 1 below:

Component Function Quantity per unit % Propylene glycol Solvent 30 ml 50 Minoxidil USP Active 3 g 5 Finasteride USP Active 0.06 g 0.1 Ethoxy diglycol Solvent 3 ml 5 reagent Latanoprost (10,000 Active 1.8 ml 0.03 mcg/ml) Absolute ethyl alcohol Solvent QS 60 ml 39.87 TOTAL 60 ml 100%

Various modifications for the preparation of the composition of the invention will be apparent to the skilled worker. Furthermore, other pharmaceutically acceptable additives such as suspending agents, emulsifying agents, non-aqueous vehicles and preservatives can be added. The techniques for the preparation of these compositions are well known in the art and reference may be had to Remington's Pharmaceutical Sciences, 18^(th) edition, Mack Publishing Co., Easton, Pennsylvania, USA 18042.

Example 2 Preparation of Composition Comprising Minoxidil

A composition comprising 5% minoxidil was prepared. Absolute ethyl alcohol was mixed with propylene glycol and heated to 55° to 65° C. The minoxidil powder was added to the alcohol/propylene glycol mixture. Ethoxy diglycol was added and the solution was stirred. The final solution was brought to volume with absolute ethyl alcohol to obtain a solution comprising 5% minoxidil.

Example 3 Preparation of Composition Comprising Finasteride

A composition comprising 0.1% finasteride was also prepared. Absolute ethyl alcohol was mixed with propylene glycol. Finasteride was added to the alcohol/propylene glycol mixture to obtain a solution having a concentration of 0.1% finasteride. Absolute ethyl alcohol also serves the function of preservative.

Example 4 Preparation of Composition Comprising Latanoprost

A solution comprising 0.03% latanoprost was prepared. Absolute ethyl alcohol was mixed with propylene glycol. The latanoprost was added to the alcohol/propylene glycol mixture. The final solution was brought to volume with absolute ethyl alcohol in order to obtain a solution having a concentration of 0.03% latanoprost. The absolute ethyl alcohol also serves the function of preservative in this composition.

Example 5

Treatment of Participants with Composition of Invention and Comparators—Analysis and Measurements

For each participant, the distance between the base of the nose and the middle of the hair crown was noted, as well as the distance separating the most distal part of the helix and the hair crown. A square area of two centimeters by two centimeters was measured around the middle point of the hair crown (marked by a washable felt crayon). Photographs were taken of each participant's scalp.

The participants were seen at monthly intervals over a six-month period and their hair was analysed in the manner described above and photographs taken.

Results

A. Treatment with Composition Comprising Finasteride, Latanoprost and Minoxidil

Each participant first had his hair analysed as described above and photographs taken. Following the first analysis, each participant was provided with a solution comprising 0.1% finasteride, 0.03% latanoprost and 5% minoxidil prepared as described in Example 1 above. The participants applied 1 ml to the scalp, once a day after cleansing. The 1 ml was applied as 10 metered dose sprays of 0.1 ml.

The results for three participants are provided. Participant 1 was a male of 61 years of age (FIG. 1 ). Participant 2 was a male of 23 years of age (FIG. 2 ) while participant 3 was a male of 29 years of age (FIG. 3 ). All three participants had androgenetic alopecia, as did the participants of the comparator groups.

FIGS. 1, 2 and 3 clearly show a marked decrease of hair loss and an increase in hair regrowth in all three participants.

B. Comparison with Treatment with Minoxidil, Finasteride and Latanoprost Alone

Each participant first had his hair analysed as described in part A above and photographs taken. Following the first analysis, each participant was provided with a solution comprising either 5% minoxidil, 0.1% finasteride, or 0.03% latanoprost. The compositions were prepared as described in Examples 2 to 4 above. The participants applied 1 ml to the scalp, once a day after cleansing. The 1 ml was applied as 10 metered dose sprays of 0.1 ml.

The results for the participants of each group are provided.

The participant for the minoxidil group was a 64 year old male. FIG. 4 shows the results obtained for this participant. Only a slight improvement in hair regrowth is observed and the results are very inferior to those seen with the composition of the invention.

Four participants used a solution of 0.1% finasteride only. These participants were respectively 30 (participant 5), 33 (participant 6), 36 (participant 7) and 46 years of age (participant 8). FIGS. 5, 6, 7 and 8 show the results for participants 5, 6, 7 and 8 respectively. Only a slight improvement in hair regrowth is observed. The results are far inferior to those seen with the composition of the invention.

Two participants used a solution comprising 0.03% latanoprost only. These participants were respectively 48 (participant 9) and 52 (participant 10) years of age. FIGS. 9 and 10 show the results for participants 9 and 10 respectively. Only a slight improvement in hair regrowth was observed. The results obtained are far inferior to those observed with the composition of the invention.

The composition comprising minoxidil, finasteride and latanoprost shows improved properties in terms of reduction of hair loss and increase of regrowth of hair when compared to a solution of 5% minoxidil alone, a solution of 0.1% finasteride alone or a solution of 0.03% latanoprost alone. The improvements shown in the reduction of hair loss and the increase of regrowth hair for the composition of the invention are superior to the improvements seen for each of the components of the composition taken individually and the results obtained to date suggest that the improvements may be superior to those of the sum of the said components.

While the composition of the invention has been tested on males, similar results are expected on females as the mechanism of hair growth is the same for both genders.

While a composition of the invention comprising a specific 5α-reductase inhibitor, namely finasteride, has been tested, it is surmised that other 5α-reductase inhibitors, will work in the same manner as finasteride. Inhibitors of form II of 5α-reductase are most preferred as the type II form of 5α-reductase is found predominantly in the hair follicles. It is also surmised that androgen receptor antagonists have an effect similar to that of finasteride in that they would lead to a decrease in the levels of DHT.

While the present invention has been described in connection with specific embodiments thereof and in a specific use, various modifications will occur to those skilled in the art. The scope of the claims should not be limited by the preferred embodiments or the examples but should be given the broadest interpretation consistent with the description as a whole. 

What is claimed is:
 1. A topical composition, comprising: (a) 2% to 5% minoxidil; (b) finasteride in an amount greater than or equal to 0.01% and less than 0.225%; and (c) 0.01% to 0.15% latanoprost, wherein the topical composition is for topical application to a scalp. 